Famed civil-rights attorney Alan Dershowitz said Tuesday he would have advised three former Hillary Clinton aides to plead the fifth before Congress in its investigation of the nominee's private server use because "there's a possibility that their answers might result in giving incriminating information."

"Any lawyer would tell them if they, in fact, did something after a subpoena was issued that there is the possibility that they may have engaged in criminal activity," Dershowitz, the Harvard Law School professor emeritus, told Megyn Kelly on Fox News. "It, too, would be a crime for Hillary Clinton or anybody on her behalf to tell these witnesses to take the Fifth Amendment.

"They can only get that advice from their lawyers. If somebody else tells them to take the fifth, that's obstruction of justice."

He told Kelly he did not believe Clinton told the three aides to cite their constitutional rights in their dealings with the House Oversight and Government Reform Committee.

"She never would have done that," Dershowitz said.

The key Clinton witness, Bryan Pagliano, did not attend the committee hearing. He is the former State Department computer specialist who set up Clinton's private server.

The other two witnesses, Bill Thornton and Paul Combetta of Platte River Networks Inc., appeared but refused to testify. They were excused from the session.

Platte River is the Denver-based company that serviced Clinton's account.

Dershowitz told Kelly he backed Oversight Committee Chairman Rep. Jason Chaffetz of Utah for subpoenaing the FBI during Monday's hearing to obtain non-redacted copies of its summary of a private interview with Clinton during the July 4th weekend.

"The FBI redacts far too many documents," he said. "That's all they do.

"The FBI has no right to make that determination unilaterally.

"We have a system of checks and balances — and Congress has a right to see anything that can't be either kept from them on good grounds," Dershowitz continued. "But there should be a presumption that congress gets it — and that presumption should be overcome only by a strong showing."

He added Clinton also should have disclosed last Friday she was diagnosed with pneumonia because otherwise "it plays into a narrative which is unfortunate.

"If Americans have a high level of distrust, then you don't want to feed into a narrative that encourages that feeling among many people."

Famed civil-rights attorney Alan Dershowitz said he would have advised three former Hillary Clinton aides to plead the fifth before Congress in its investigation of the nominee's private server use because "there's a possibility that their answers might result in giving incriminating information."